Dissertationen zum Thema „Chromtography coupled to a mass spectrometer“
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Boulesteix, David. „Optimization of extraterrestrial organic matter extraction methods to detect and classify physical and (bio)chemical gnostic and agnostic bioindicators and biosignatures through a transversal analytical study“. Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPASJ017.
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Au cours de cette thèse, nous avons fourni des éléments de réponse pour les problématiques d'exploration spatiale : i) Quelles signatures recherchons-nous pour des traces de vie et/ou une chimie prébiotique sur les surfaces planétaires de notre système solaire ? et ii) Comment pouvons-nous les détecter ? Quelle méthode de préparation des échantillons est la plus adéquate pour une analyse GC-MS spatiale ? ainsi que pour les problématiques fondamentales : i) Comment s'est déroulé la transition entre une chimie prébiotique abiotique et une chimie biotique ? Y a-t-il une limite nette ou un état de transition que l'on pourrait défnir comme « biochimie primitive » ? et ii) Quel est l'influence de chaque paramètre environnemental sur la dégradation/transformation de cette matière organique abiotique ou biotique ?L'application d'une approche transdisciplinaire a permis non seulement de préparer les instruments GC-MS spatiaux avec des analogues définit par des caractéristiques communes aux surfaces planétaires extraterrestres explorées mais aussi d'identifier des précurseurs, bioindicteurs et bisoignatures que l'on a sous catégorisé comme agnostique d'une vie quelconque ou gnostique assimilé à la vie terrestre connue.Les protocoles d'extraction de matière organique optimisés dans cette thèse ont permis l'application de protocole spatial pour une approche de métabolomique environnementale non ciblée et ainsi identifier des populations au sein des environnements analogues investigués et des molécules essentielles à l'adaptation au milieu et préservation face aux sels, irradiations et biodisponibilité de l'eau et de nutrimentsDuring this thesis, we provided elements of answers for space exploration issues: i) What signatures are we looking for traces of life and/or prebiotic chemistry on the planetary surfaces of our solar system? and ii) How can we detect them? Which sample preparation method is most suitable for spatial GC-MS analysis? as well as for fundamental issues: i) How did the transition take place between abiotic prebiotic chemistry and biotic chemistry? Is there a clear boundary or transition state that could be defined as “primitive biochemistry”? and ii) What is the influence of each environmental parameter on the degradation/transformation of this abiotic or biotic organic matter?The application of a transdisciplinary approach has made it possible not only to prepare space GC-MS instruments with analogues defined by characteristics common to the extraterrestrial planetary surfaces explored but also to identify precursors, bioindicators and bisignatures that we have under categorized as agnostic of any life or gnostic assimilated to known earthly life.The organic matter extraction protocols optimized in this thesis allowed the application of spatial protocols for a non-targeted environmental metabolomics approach and thus identify populations within the analogous environments investigated and molecules essential for adaptation to the environment and preservation against salts, irradiation and bioavailability of water and nutrients
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Macedone, Jeffrey Harris. „Ion Transmission in the first vacuum stage of an Inductively Coupled Plasma Mass Spectrometer“. BYU ScholarsArchive, 2005. https://scholarsarchive.byu.edu/etd/274.
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The inductively coupled plasma mass spectrometer (ICP-MS) is the instrument of choice for trace and ultra-trace elemental analysis. However, the ICP-MS suffers from matrix effects. Matrix effects occur when instrument response varies as the composition of the sample matrix is changed. Matrix effects, or non-spectroscopic interferences, limit the accuracy of routine analysis. Identification of the sources of matrix effects provide a basis for reducing or eliminating them. As inaccuracies in the ICP-MS are more severe than those in the ICP atomic emission spectrometer, the problem may be due, at least in part, to the vacuum interface used to couple the plasma source and mass spectrometer. The research herein is a study of matrix effect sources in the first stage of the vacuum interface. This study utilized laser-induced fluorescence of atomic species to identify factors affecting analyte transport through the sampling orifice of the vacuum interface. Several non-idealities in the performance of the interface were found. (1) Operating conditions and sample compositions can negatively affect the efficiency with which ions are extracted through the vacuum interface coupling the plasma source to the mass spectrometer. (2) The sampling cone itself was found to suppress and narrow ion distributions in the plasma. (3) Changes in the degree of ionization were identified in the first vacuum stage. The evidence of recombination and state-changing collisions was observed in the first vacuum stage at lower power settings. Matrix effects occur in the first vacuum stage, the first step of the ion extraction process. This work shows that changes in ion transport through the first vacuum stage of the vacuum interface of an ICP-MS affect the overall performance of the instrument.
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Macedone, Jeffrey Harris. „Ion transmission studies in the first vacuum stage of an inductively coupled plasma mass spectrometer /“. Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd785.pdf.
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Rogers, Duane A. „Development and characterization of an inductively coupled plasma/electrospray ionization dual-source time-of-flight mass spectrometer“. [Bloomington, Ind.] : Indiana University, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3386716.
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Thesis (Ph.D.)--Indiana University, Dept. of Chemistry, 2009.Title from PDF t.p. (viewed on Jul 22, 2010). Source: Dissertation Abstracts International, Volume: 70-12, Section: B, page: 7533. Adviser: Gary M. Hieftje.
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Somers, William R. „Testing Direct Simulation Monte Carlo Methods Against the Fluid Equations in the Inductively Coupled Plasma Mass Spectrometer“. Diss., CLICK HERE for online access, 2008. http://contentdm.lib.byu.edu/ETD/image/etd2621.pdf.
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6
Radicic, William Neil. „Velocity and Temperature Characterization of the First Vacuum Stage Expansion in an Inductively Coupled Plasma - Mass Spectrometer“. Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd435.pdf.
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7
Ma, Haibin. „Ion Transport Behaviors Upstream and Downstream from the Sampling Cone of an Inductively Coupled Plasma Mass Spectrometer“. BYU ScholarsArchive, 2009. https://scholarsarchive.byu.edu/etd/2196.
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Inductively coupled plasma - mass spectrometry (ICP-MS) is the technique of choice worldwide for trace elemental determinations because of its excellent ionization ability, low detection limits and fast analysis speeds. However, the ICP-MS still suffers from some disadvantages, such as spectral overlap and severe matrix effects. Matrix effects or interferences, partly arise from changes in the analyte transmission through the interfacial region between the ICP and mass spectrometer with changes in sample matrix. Better understanding of the transmission behaviors of analyte through the sampling and skimmer cones will provide the insights needed to alleviate matrix interferences and to improve the interface design between the ICP and mass spectrometer. Laser induced fluorescence is a highly sensitive, non-invasive and element specific detection method. The research herein endeavors to explain the transport behaviors of analytes upstream and downstream from the sampling cone in an ICP-MS. The final goal of this research is to improve the consistency and efficiency with which ions are transported from an ICP source to a mass analyzer. Several issues related to analyte transmission through the sampling and skimmer cones have been explored and discussed in this dissertation. First, it is found that the existence of the sampling cone not only disturbs the local thermodynamic equilibrium of the plasma, but also changes the spatial distributions and number densities of analyte species. Second, it has been verified that the spread of analyte species in the first vacuum stage is mass-dependent and can be explained by ambiploar diffusion theory. Finally, the current research suggests that the transmission efficiencies of the skimmer cone are impacted by the nebulizer flow and first vacuum stage pressure of the ICP-MS. To better elucidate the analyte transport behaviors from the plasma to the ion detector in an ICP-MS, more investigation needs to be carried out. Further research, such as the entire measurements of analyte transmission efficiency through the skimmer cone, the variation of doubly charged ions under different plasma operational conditions, and the functions of argon metastable atoms on analyte ionization inside the plasma will require much additional work.
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Vail, Teresa M. „Rapid identification, confirmation, and quantitation using an open-air ion source coupled to a time-of-flight mass spectrometer“. Scholarly Commons, 2007. https://scholarlycommons.pacific.edu/uop_etds/666.
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The ability to identify and confirm a compound using mass spectrometry usually involves time consuming sample preparation and method development. The open-air ion source DART (Direct Analysis in Real Time) can ionize compounds in the gas, solid, or liquid phase without chromatography or sample preparation due to the interactions of helium metastable atoms with gas molecules commonly found in air. The coupling of the DART to a time-of-flight (TOF) mass spectrometer allows the rapid determination of an analyte's elemental composition based on accurate mass measurement and isotope peak intensities. Mass spectrometric fragmentation data can aid in the structural identification of an analyte as compounds produce characteristic fragment-ions based on their structure. The TOP's ability to produce fragmentation spectra was compared to the more traditional tandem mass spectral method (MS/MS) considering the TOF lacks the ability to select pre-cursor ions. The TOF produced in-source CAD (collisionally activated dissociation) spectra comparable to MS/MS spectra for three well known pharmaceuticals acetaminophen, phenylbutazone and clenbuterol. Further structural confirmation was explored through a determination of the number of active hydrogen atoms in an analyte molecule achieved by hydrogen/deuterium (H/D) exchange by treatment with deuterium oxide (D20) in the DART sample gap. Mass spectra acquired in the presence of D20 of analytes containing active hydrogen atoms associated with hydroxyl, amino and carboxylic acid groups showed that H/D exchange was predictable and reproducible.
Using accurate mass measurement and isotope peak intensities, the elemental composition of an unknown captured on filter paper was identified as dipropylene glycol (DPG) analyzed directly from the surface of the filter paper. Data from in-source CAD and H/D exchange of both the unknown and authentic standards confirmed that the unknown was DPG. The cross-correlation of accurate mass measurement and isotope peak intensities, in-source CAD and HID exchange data provided an unambiguous identification of the contaminant melamine in dog food without the need for any sample preparation.
Once analytes are identified and confirmed, quantitation of the analyte is desirable. The calibration curves here are constructed using the net extracted ion-current associated with the analyte relative to the internal standard. In cough syrup, a complicated matrix, the linearity, R2, is shown to be 0.992.
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Zachreson, Matthew R. „Comparing Theory and Experiment for Analyte Transport in the First Vacuum Stage of the Inductively Coupled Plasma Mass Spectrometer“. BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/3538.
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The Direct Simulation Monte Carlo algorithm as coded in FENIX is used to model the transport of trace ions in the first vacuum stage of the inductively coupled plasma mass spectrometer. Haibin Ma of the Farnsworth group at Brigham Young University measured two radial trace density profiles: one 0.7 mm upstream of the sampling cone and the other 10 mm downstream. We compare simulation results from FENIX with the experimental results. We find that gas dynamic convection and diffusion are unable to account for the experimentally-measured profile changes from upstream to downstream. Including discharge quenching and ambipolar electric fields, however, makes it possible to account for the way the profiles change.
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Zachreson, Matthew R. „Comparing Theory and Experiment for Analyte Transport in the First Vacuum Stage of the Inductively Coupled Plasma Mass Spectrometer“. BYU ScholarsArchive, 2015. https://scholarsarchive.byu.edu/etd/5610.
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The inductively coupled plasma mass spectrometer (ICP-MS) has been used in laboratories for many years. The majority of the improvements to the instrument have been done empirically through trial and error. A few fluid models have been made, which have given a general description of the flow through the mass spectrometer interface. However, due to long mean free path effects and other factors, it is very difficult to simulate the flow details well enough to predict how changing the interface design will change the formation of the ion beam. Towards this end, Spencer et al. developed FENIX, a direct simulation Monte Carlo algorithm capable of modeling this transitional flow through the mass spectrometer interface, the transitional flow from disorganized plasma to focused ion beam. Their previous work describes how FENIX simulates the neutral ion flow. While understanding the argon flow is essential to understanding the ICP-MS, the true goal is to improve its analyte detection capabilities. In this work, we develop a model for adding analyte to FENIX and compare it to previously collected experimental data. We also calculate how much ambipolar fields, plasma sheaths, and electron-ion recombination affect the ion beam formation. We find that behind the sampling interface there is no evidence of turbulent mixing. The behavior of the analyte seems to be described simply by convection and diffusion. Also, ambipolar field effects are small and do not significantly affect ion beam formation between the sampler and skimmer cones. We also find that the plasma sheath that forms around the sampling cone does not significantly affect the analyte flow downstream from the skimmer. However, it does thermally insulate the electrons from the sampling cone, which reduces ion-electron recombination. We also develop a model for electron-ion recombination. By comparing it to experimental data, we find that significant amounts of electron-ion recombination occurs just downstream from the sampling interface.
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Edmund, Alisa Jane. „Laser-Induced Fluorescence Imaging of Calcium and Barium Ion Beams in the Second Vacuum Stage of a Commercial Inductively Coupled Plasma Mass Spectrometer“. BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/4135.
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Inductively coupled plasma-mass spectrometers (ICP-MS) have become the workhorses of many analytical labs over the past few decades. Despite the instruments' high sensitivities and low detection limits there is still a demand for improvements in several aspects of their performance. One area of improvement is in the understanding of "space charge effects" Space charge effects are classified as problems associated with the ion beam. Problems are created when the mutual repulsions of the ions make consistent focusing of the ion beam difficult. This is particularly problematic with samples containing a low concentration analyte contained within a high salt solution matrix, resulting in lower instrument sensitivity and inaccurate results. The research presented here used laser-induced fluorescence (LIF) imaging to characterize the ion beam as it enters the mass analyzer of a commercial ICP-MS. To perform the LIF imaging a laser system with two ring cavities was constructed to frequency double a CW titanium-sapphire laser to the calcium ion transition at 393.4 nm or to the barium ion transition at 455.4 nm. Ion beam images for both elements were taken under different instrument modes and matrix compositions. The same trends in shift and distortion of the barium ion beam with the addition of a lead matrix was observed as in previous experiments with calcium. A shift in the focal point of the ion beams of both elements was also observed in normal sensitivity mode and with the instrument's collisional reaction interface (CRI). This work indicates that a shift in beam focusing is responsible for the change in ion transmission due to changes in matrix composition and instrument modes.
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Wu, Shitou [Verfasser], Gerhard [Akademischer Betreuer] [Gutachter] Wörner und Klaus [Gutachter] Simon. „Laser Ablation-Inductively Coupled Plasma-Mass Spectrometer (LA-ICP-MS) in Geosciences: Further Improvement for Elemental Analysis / Shitou Wu ; Gutachter: Gerhard Wörner, Klaus Simon ; Betreuer: Gerhard Wörner“. Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2017. http://d-nb.info/113991121X/34.
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Le, Maître Johann. „Développement de la spectrométrie de masse à ultra- haute résolution associée à la spectrométrie de mobilité ionique pour la caractérisation de coupes pétrolières lourdes. structural analysis of heavy oil fractions afterr hydrodenitrogenation by high-resolution tandem mass spectrometry and ion mobility spectrometry Structural analysis of neutral nitrogen compounds refractory to the hydrodenitrogenation process of heavy oil fractions by high-resolution tandem mass spectrometry and ion mobility-mass spectrometry Chemical characterization of 15 biocrudes obtained from hydrothermal liquefaction of industrially cultivated wild micro algae Chemical characterization with different analytical techniques, a way to understand the process: Case of the paraffinic base oil production line Exploring complex mixtures by cyclic ion mobility high-resolution mass spectrometry – Application towards Petroleum. Simulation and modeling of Collision Cross Section for structural elucidation of heavy oil fraction by ion mobility-mass spectrometry: Using polyaromatic hydrocarbons compounds mixture as calibration standard Characterization of sulfoxides compounds in dimeric distribution of heavy oil fractions by positive-ion electrospray ionization FTICR mass spectrometry Structural analysis of Petroporphyrins from asphaltene by trapped ion mobility coupled with a Fourier transform ion cyclotron resonance mass spectrometer. Cyclic ion mobility spectrometry coupled to high-resolution time-of-flight mass spectrometry equipped with atmospheric solid analysis probe for the molecular characterization of combustion particulate matter. Structural study of analogues of Titan’s haze by trapped ion mobility coupled with a Fourier transform ion cyclotron mass spectrometer“. Thesis, Normandie, 2020. http://www.theses.fr/2020NORMR051.
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L'évolution des réserves de pétrole implique l'utilisation en raffinerie de pétroles bruts non conventionnels, bien souvent plus lourds et donc difficiles à caractériser. Les produits pétroliers sont en effet des mélanges chimiques extrêmement complexes. La partie légère et volatile peut être analysée par chromatographie en phase gazeuse couplée à la spectrométrie de masse (GC/MS), permettant l'identification des composés par l'utilisation de mesures de masses précises et de modèles de fragmentation. Cependant ces techniques sont inadaptées à l'analyse des fractions lourdes. Dans la pratique, la caractérisation des mélanges les plus complexes implique l'utilisation de spectromètres de masse à ultra-haute résolution généralement par analyse directe sans séparation chromatographique. La technique de référence est aujourd’hui la spectrométrie de masse à transformée de Fourier par résonance cyclotronique des ions (FTICR). Grâce à une résolution supérieure à 106 et à une précision de mesure de masse inférieure à 0,1 ppm, cet instrument permet de séparer toutes les espèces présentes dans un produit pétrolier et d'attribuer à chaque valeur de m/z une composition élémentaire unique. Ceci permet d'obtenir très facilement des cartes moléculaires qui peuvent être présentées graphiquement en utilisant le diagramme de Kendrick, le diagramme de van Krevelen ou le nombre d'insaturations (DBE) en fonction du nombre de carbones. Ce travail de thèse a permis grâce à la caractérisation moléculaire de produits pétroliers (Vacuum Gas Oil, Pétroles Bruts, Matériel Interfacial, Asphaltènes et Bio-Oil…) d'aborder la complexité de leur traitement dans l’outil de raffinage. Des protocoles d'analyses des échantillons ont été développés, à l'aide de différentes sources d'ionisation à pression atmosphérique (ESI, APCI et APPI) ainsi que par désorption/ionisation laser (LDI) sur le spectromètre de masse FTICR 12T. Les informations sur le contenu isomérique des produits pétroliers ont ensuite été déterminées grâce à l'apport de la spectrométrie de mobilité ionique (IMS)The evolution of oil reserves requires the use in refineries of unconventional crude oils, which are often heavier and therefore difficult to characterize. Petroleum products are in fact extremely complex chemical mixtures. The light and volatile part can be analysed by gas chromatography coupled with mass spectrometry (GC/MS), allowing the identification of compounds by using precise mass measurements and fragmentation models. However, these techniques are inappropriate for the analysis of heavy fractions. In practice, the characterization of the most complex mixtures involves the use of ultra-high-resolution mass spectrometers generally by direct analysis without chromatographic separation. The reference technique today is Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FTICR). With a resolution of more than 106 and a mass measurement accuracy of less than 0.1 ppm, this instrument can separate all the species present in a petroleum product and assign a unique elemental composition to each m/z value. This makes it very easy to obtain molecular maps that can be presented graphically using the Kendrick diagram, the van Krevelen diagram or the number of unsaturations (DBE) as a function of the number of carbons. This thesis work has allowed thanks to the molecular characterization of petroleum products (Vacuum Gas Oil, Crude Oil, Interfacial Material, Asphaltenes and Bio-Oil...) addressing the complexity of their treatment in the refining tool. Protocols for sample analysis have been developed, using different sources of ionization at atmospheric pressure (ESI, APCI and APPI) as well as laser desorption/ionization (LDI) on the FTICR 12T mass spectrometer. Information on the isomeric content of petroleum products was then determined using ion mobility spectrometry (IMS)
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Maillard, Julien. „Composition chimique du brouillard de Titan par mobilité ionique couplée à la spectrométrie de masse haute résolution Comparison of soluble and insoluble organic matter in analogues of Titan's aerosols Optimization of ion trajectories in a dynamically harmonized Fourier-Transform Ion Cyclotron Resonance cell using a Design of Experiments strategy Structural Study of Analogues of Titan's Haze by Trapped Ion Mobility Coupled with a Fourier Transform Ion Cyclotron Mass Spectrometer. High resolution mass spectrometry for future space missions: comparative analysis of complex organic matter with LAb-CosmOrbitrap and LDI-FTICR. Structural elucidation of soluble organic matter: Application to Titan's haze. Dark-ageing of analogues of aerosols in the atmosphere of the early Earth“. Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASV023.
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Bien que l’enjeu prébiotique soit important, l’étude des aérosols présents dans l’atmosphère de Titan, la plus grosse lune de Saturne, reste un challenge pour la communauté scientifique. En effet, les données récoltées par les sondes Voyager et Cassini-Huygens ont permis de récupérer les premières informations mais pas de percer les secrets de ce brouillard de particules. Le but de cette thèse est d’étudier la composition chimique de ces aérosols grâce à leur reproduction sur Terre. La première approche présentée est la caractérisation moléculaire par le biais de la spectrométrie de masse à ultra haute résolution (FTICR). Dans cette partie sera présenté la comparaison entre les fraction soluble et insoluble de ces échantillons et leur vieillissement en présence d’oxygène.Ensuite, l’investigation de la croissance de ces aérosols est présentée par l’utilisation de spectrométrie de masse en tandem.La dernière partie de cette thèse présente l’étude de la structure tridimensionnelle. Pour cela, la mobilité ionique couplée à la spectrométrie de masse a été utilisée et sera reporté en deux partie, l’une en TWIMS-Synapt et l’autre en TIMS-FTICR. Enfin une étude en Atomic Force Microscopie sera présentée et permettra de montrer de vraies structures de molécules présentes dans les aérosols grâce au grossissement fournit par ce type de microscopeAlthough the prebiotic challenge is important, the study of aerosols in the atmosphere of Titan, Saturn's largest moon, remains a challenge for the scientific community. Indeed, the data collected by the Voyager and Cassini-Huygens probes made it possible to retrieve the first information but not to unlock the secrets of this particle fog. The purpose of this thesis is to study the chemical composition of these aerosols through their reproduction on Earth. The first approach presented is molecular characterization using high resolution mass spectrometry. In this section, the comparison between the soluble and insoluble fraction of these samples and their ageing will be presented. Then, the investigation of the growth of these aerosols is presented through the use of tandem mass spectrometry. The last part of this thesis presents the study of the three-dimensional structure. For this purpose, ion mobility coupled with mass spectrometry has been used and will be reported in two parts, one in TWIMS-Synapt and the other in TIMS-FTICR. Finally, a study in Atomic Force Microscopy will be presented and will make it possible to show real structures of molecules present in aerosols thanks to the magnification provided by this type of microscope
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Lu, Chien-Wei, und 呂健瑋. „Application of Trace Element Analyses by Inductively Coupled Plasma Mass Spectrometer“. Thesis, 2019. http://ndltd.ncl.edu.tw/handle/95p57y.
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博士國立交通大學
應用化學系碩博士班
107
Inductively coupled plasma mass spectrometer (ICP-MS) coupled with variety pretreatments and introduction systems for the trace elements analysis was utilized in the different applications in this study. The first part, ICP-MS was applied to analyze the metal ion impurity in the tetraethyl orthosilicate (TEOS) which is used for semiconductor manufacturing. With a simple liquid-liquid extraction approach, the metal ion in TEOS was transfered into water by adding an assisting agent and was quantified by ICP-MS with concentration effort. Such a method could be used to routine quality control and further extended to analyze other organic materials with trace metal ion impurity. In the second part, a gas sampling system, consists of two impingers and porous tubes, was developed to collect the trace metal ion in nitrogen, hydrogen, helium and hydrogen chloride gases into the specific absorption solution. Then the metal ion in these gases can be quantified by ICP-MS. In the third part, the ICP-MS coupled with the organic introduction system method was used to quantify the concentrations of metal ion impurities in in-plane-switching (IPS) type polyimide (PI) alignment solution. This method can be used not only for routine and large-scale sample analyses but also for studying contamination phenomena during the PI patterning process and for determining the leaching rates of trace metals from bottles. Finally, we developed an ICP-MS method to directly analyze the total sulfur content in petroleum fuel samples.With simple dilution approach of various organic solvent system in specific dilution factor, gasoline and diesel samples were able to have an accurate sulfur concentration by external calibration way. The accuracy of the developed method was evaluated by examining fourteen international proficiency testing samples containing gasoline, ethanol-blended gasoline, diesel and biodiesel obtained from the American Society for Testing and Materials and the Institute for Interlaboratory Studies. The described method is suitable for routine analysis of total sulfur content in petroleum fuels with the combination of an automatic injection system.
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Balsanek, William John. „Conducting multi-elemental analyses with an inductively coupled plasma mass spectrometer using electrothermal vaporization sample“. Thesis, 2005. http://hdl.handle.net/2152/2389.
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Hsu, Chu-Jung, und 許祝榮. „Establishment of liquid chromatography coupled inductively coupled plasma mass spectrometer for detection of mercury species in commercial fish meat“. Thesis, 2019. http://ndltd.ncl.edu.tw/handle/4gy7gj.
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碩士國立高雄科技大學
水產食品科學系
107
Mercury is a common heavy metal pollutant. Among them, methylmercury, a metabolite formed by microbial metabolic conversion, is the most toxic, 10 to 100 times more toxic than general inorganic mercury. The purpose of this study was to establish a simple, practical, and fast method for the determination of methylmercury in fish and shellfish. This liquid chromatography coupled to inductively coupled plasma mass spectrometry (LC-ICP-MS) was used to determine mercury species including the separation and quantification of methylmercury (Me-Hg), propylmercury (Pr-Hg) and divalent mercury (Hg2+). The chromatographic column, mobile phase pH, ICP-MS plasma power in-tensity and aerosol gas flow rate, and sample extraction solution condi-tions are optimized. Moreover, the LC-ICP-MS was established to de-termine the validity of the fish samples, and the mercury species in the edible meat were analyzed by the established method for the fish sold in southern Taiwan. The results showed that the mixed solution of 50 mM L-cysteine and 50 mM sodium perchlorate (pH=4.0) used as the mobile phase, and IonPacTM CS5A (4×250 mm, 9.0 μm) column with ion exchange resin for LC method are the optimum conditon. In ICP-MS condition, the plasma power set at 1550 W and the carrier flow rate of 0.96 L/min are the op-timum conditions for analysis. In addition, 0.04, 0.1 and 0.2 mg/kg concentrations of Me-Hg, Pr-Hg and Hg2+ standards were spiked to fish samples, and the average recovery (accuracy), repeatability (CV%) and intermediate precision (CV%) obtained by LC-ICP-MS ranged from 86.13 to 101.37%, 1.45 to 3.69% and 1.85 to 5.01%, respectively, all in accordance with the validation of food chemical testing methods. Moreover, the analysis of the fish sold in southern Taiwan by the es-tablished method showed that the methylmercury contents in tuna and marlin fish meats, and salmon and cobia fish meats all were lesser than the methylmercury limit of food hygienic standard (2 mg/kg and 0.5 mg/kg, respectively).
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Hung, Huan-Yi, und 洪煥毅. „Application of Trace Metal Analyses by Inductively Coupled Plasma Mass Spectrometer with Organic Solvent Introduction System“. Thesis, 2012. http://ndltd.ncl.edu.tw/handle/55139137799867941692.
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博士國立交通大學
應用化學系碩博士班
100
Inductively Coupled Plasma Mass Spectrometer (ICP-MS) coupled with the organic introduction system for the trace metal ions analyses was utilized in the different applications in this study. The first part, ICP-MS was applied to the trace metal analyses of liquid crystal and polyimide alignment solution that used in the TFT-LCD industry. With simple dilution approach of various organic solvent system, liquid crystal and polyimide alignment solution was able to have an accurate metal ions concentration by external calibration way. The analytical results proved the bad effects of trace metal ions in TFT-LCD, in addition, the permissive metal ions concentration could be estimated to be about 40 µg L-1 roughly in the liquid crystal inside TFT-LCD panel. In the second part, we used the ICP-MS in the corrosive detection of underground pipelines, fittings and storage tanks at gas stations. This study developed a method to check the differences of Zn, Cu, and Fe concentrations between gasoline or diesel samples of various gas stations. The samples are taken easily from a refueling gun at the gas station and analyzed directly in ICP-MS with different organic solvent dilution. The different trace metal ions were statistical from the normal gas station samples for comparison with those from abnormal gas stations where oil leakages were comfirmed. The results demonstrated that trace metal ions variations in gasoline or diesel samples could be used to predict the corrosive situation of underground pipelines, fittings and storage tanks. For example, Zn concentrations in the normal gasoline samples were generally lower than 8 ?慊 L-1, it would be confirmed that corrsive situation was taking place in more than 9.56 ?慊 L-1 of Zn concentration in the gasoline sample or 10.27 ?慊 L-1 of Zn in the diesel sample. The ICP-MS method was easier and faster than the traditional method for checking the corrosion of a pipeline, a fitting and a storage tank, in theory, it could prevent further oil leakage pollution because the metal ions concentration change would be detected before the actually oil leakage in our method. Finally, we coorperate with Biomedical Teconology and Research Laboratories to set up a process in early assessment of radiopharmaceutical with 188Re in brachytherapy by inductively coupled plasma atomic emission spectrometer (ICP-AES) and ICP-MS. By using the pharmaceutical with the non-radioactive element of 187Re instead of 188Re, we could use the ICP-AES and ICP-MS to have a quantitative analysis about in vitro and in vivo dissolution of 187Re in the trace concentration. Obviousely, this could reduce the costs and risks when we carried out with non-radioactive 187Re in the preliminary radiopharmaceutical research.
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Wu, Shitou. „Laser Ablation-Inductively Coupled Plasma-Mass Spectrometer (LA-ICP-MS) in Geosciences: Further Improvement for Elemental Analysis“. Doctoral thesis, 2017. http://hdl.handle.net/11858/00-1735-0000-0023-3EF8-1.
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20
Liao, Chien-Fu, und 廖健富. „Multi-dimensional high-performance liquid chromatography online coupled to mass spectrometer for short peptide amino acid sequence determination“. Thesis, 2015. http://ndltd.ncl.edu.tw/handle/79185238437452188893.
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碩士中原大學
化學研究所
103
Online column-switching technique and online heart-cutting sampling technique coupled multidimensional liquid chromatography mass spectrometric system was developed and used for the development of an amino acid sequencing method by using short peptides such as the dipeptide Aspartame and the tripeptide Glutathione. The first dimension column was an affinity chiral chromatographic column which was used for the separation of peptides and amino acids produced from the electric-thermal hydrolysis of short peptides and detected by an UV detector. Except cysteine, the amino acids separated by the first dimension chromatographic column were transferred to the second dimension ligand-exchange chromatographic column for further separation to learn about the kind of amino acid and the type of its enantiomer by a fluorescence detector. Then, the peptide products and cysteine separated by the first dimension chromatographic column were sequentially transferred to the other second dimension reversed-phase chromatographic column for further separation and detected by an ion-trap mass spectrometer to obtain the molecalur werght and characteristic mass fragment ion signal of various peptide products and cysteine. Finally, the amino acid sequence of the studied short peptide was determined in accordance with the order of "small peptide to large peptide" by matching the molecular weight of previously determined amino acids and the molecular weight information of peptide from mass spectrometry through the method of permutation and combination. The novel "botom-up" amino acid sequencing method for short peptides has been used for determining the amino acid sequence of the dipeptide Aspartame and the tripeptide Glutathione. The determined amino acid enantiomers were L-aspartic acid and L-phenylalanine for Aspartame. The determined amino acid enantiomers were glycine, L-glutamic acid, and L-cysteine for Glutathione. In the positive ion detection mode of the ion-trap mass spectrometry, the molecular mass signal of dipeptide m/z 281 ([AspPhe+H]+) and the N-terminal carbo cation signal of m/z 116 ([AspPhe-phe]+) confirms that the amino acid sequence for Aspartame is "Aspartyl-phenylalanine (AspPhe)". Then, by trial-and-error, a methoxide functional group was modified on the C-termal phenylalanine to give a mass signal of m/z 180 ([AspPheOCH3-Asp+2H]+) and a mass signal of m/z 295 ([AspPheOCH3+H]+). Therefore, the structure of Aspartame is aspartyl phenylalamine methyl ester (AspPheOCH3). Similarly, the amino acid sequence of the tripeptide Glutathione was determined first by confirming the three constituents amino acid enantiomers, i.e. glycine, L-glutamic acid, and L-cysteine. Then, under the positive ion detection mode of mass spectrometer, the molecular mass signals of the two dipeptides m/z 251 ([GluCys+H]+) and m/z 179 ([CysGly+H]+) and their corresponding N-terminal carbon cation mass fragmentation signals were confirmend to suggest the tripeptide GluCysGly. Finally, the two N-terminal carbo cation mass fragmentation signals of m/z 130 ([GluCysGly-CysGly]+) and m/z 233 ([GluCysGly-Gly]+) and the tripeptide mass signal of m/z 308([GluCysGly+H]+) were identified to confirm the amino acid sequence of glutathione as "glutamyl-cysteinyl-glycine (GluCysGly)". The limit of detection (LOD) of the fluorescence detector for the amino acid enantiomers of L-aspartic acid, L-phenylalanine, glycine, and L-glutamic acid were in the range of 0.03-0.28 μg mL-1; the LOD of the ion-trap mass spectrometer for the dipeptides "aspartyl-phenylalanine", "glutamyl-cysteine", and "cysteinyl-glycine", Aspartame, Glutathione, and L-cysteine were in the range of 1.04-2.46 ng mL-1.
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Lin, Shang-Wei, und 林上為. „Measurement of Neutral Gas Densities in the Inductively Coupled Plasma by Mass Spectrometer for Investigating the Neutral Gas Heating Effect“. Thesis, 2007. http://ndltd.ncl.edu.tw/handle/47237825471209834200.
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22
Lin, Huei-Ting, und 林卉婷. „Improved measurements for high precision and high sensitivity uranium isotopic ratio and concentration by quadrupole inductively coupled plasma mass spectrometer“. Thesis, 2005. http://ndltd.ncl.edu.tw/handle/77503158076612394530.
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碩士國立臺灣師範大學
地球科學系
93
Uranium isotopic composition and concentration have been widely applied to various fields in the earth sciences. This work focused on the improvement of analytical technique for uranium isotopic ratio and concentration measurements by Quadrupole Inductively Coupled Plasma Mass Spectrometer (Q-ICPMS). To approach the goal of permil-level analytical precision with only ng-U sample sizes, three strategies were applied. First, the Q-ICPMS was connected to a micro-concentric nebulization (MCN) introduction system to amplify sensitivity and to reduce required sample size. Standard deviation filters were then used to remove outliers to improve precision and accuracy. Finally, the 233U-236U double spikes were added and then data were processed with the standard bracketing method to correct mass fractionation and ratio drifting and, therefore, higher precision and accuracy could be achieved. The results showed that the overall sensitivity (ion detected/ atoms introduced) was about 0.3~0.4. Oxide and hydride levels are less than 0.3% and 2 ppm, respectively. Under measurement time of 15-20 minutes, U standards with 30 ng of U give within-run precisions better than 3.3 (±2 R.S.D.) for 234U and better than 3.1 (±2 R.S.D.) for [238U]. Replicate measurements made on standards reveal that between-run precision of 4.1 (±2 R.S.D.) for 234U and 2.4 (±2 R.S.D.) for [238U] can be achieved. Measurements of U isotopic ratios and concentrations in coral, sea water, and speleothem samples show averaged 234U and [238U] within-run precisions of 5 and 5.5, respectively. All measurements made by this work reveal no significant difference from the values measured by High Resolution ICPMS (Li et al., 2005; X. Wang unpublished data) in the 95% confidence interval.
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Escorcia, Egda Nadyr. „Laboratory Aerosol Kinetics Studies of the Hydrolysis Reaction of N2O5 Using a Flow Tube Coupled to a New Chemical Ionization Mass Spectrometer“. Thesis, 2010. http://hdl.handle.net/1807/24565.
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The hydrolysis reaction of N2O5 was investigated at room temperature on two aerosol types using a flow tube coupled to a newly built Chemical Ionization Mass Spectrometer (CIMS). This instrument was fully constructed and optimized during this research period, as well as employed to conduct one of two aerosol studies. The first examined the reaction on ammonium bisulphate aerosols using a new ion detection method, I-•N2O5 cluster formation, which proved to be highly advantageous over the common approach of dissociative charge transfer, yielding a sensitivity for I-•N2O5 of 0.024 Hz/pptv. The uptake coefficients at 30% and 50% relative humidity were 0.0067 ± 0.0002 and 0.0120 ±0.0014, respectively. The second study was performed using a different CIMS previously assembled in the laboratory. In this case, the reaction was investigated on secondary organic aerosols produced through the ozonolysis of α-pinene, and resulted in an uptake coefficient of 8.5x10-5 ± 7x10-6 at 0% relative humidity.